The CX style of bike is designed to be raced unladen. Some have sufficient braze-ons to add a rack and handle OK with a hostelling load. They make very good general purpose bikes.

For an expedition bike, you should get a bike designed as an expedition bike. This would have more stable geometry, longer chanstays to give heel clearance and put the weight inside the wheelbase. It would also have touring forks with rack mounting, 3 water bottle mountings, 2 threads at the rear dropouts, lower touring ratio gears, and gear changers with a friction backup mode. Touring wheels are much heavier duty than CX racing wheels, and have a min of 36 spokes and thicker wear-resistant rims.

Bruce Gorden makes about the best value one around, the BLT. I would recomend the version using 26" MTB wheels rather than 700c for your journey. His luggage racks are also excellent.